Correct unused parameters in the copying algorithms (#8232)

Starting in CUDA 11.3, nvcc will start to unconditionally warn about unused parameters on functions/methods that are in anonymous namespaces.

Authors:
  - Robert Maynard (https://github.com/robertmaynard)

Approvers:
  - David Wendt (https://github.com/davidwendt)
  - Mark Harris (https://github.com/harrism)

URL: #8232

cpp/include/cudf/detail/copy_if.cuh

@@ -278,9 +278,9 @@ struct scatter_gather_functor {
   std::unique_ptr<cudf::column> operator()(
     cudf::column_view const& input,
     cudf::size_type const& output_size,
-    cudf::size_type const* block_offsets,
+    cudf::size_type const*,
     Filter filter,
-    cudf::size_type per_thread,
+    cudf::size_type,
     rmm::cuda_stream_view stream,
     rmm::mr::device_memory_resource* mr = rmm::mr::get_current_device_resource())
   {

cpp/src/copying/contiguous_split.cu

@@ -255,7 +255,6 @@ __device__ void copy_buffer(uint8_t* __restrict__ dst,
  */
 template <int block_size>
 __global__ void copy_partition(int num_src_bufs,
-                               int num_partitions,
                                uint8_t** src_bufs,
                                uint8_t** dst_bufs,
                                dst_buf_info* buf_info)
@@ -447,6 +446,13 @@ struct buf_info_functor {
     return {current + 1, offset_stack_pos + offset_depth};
   }
 
+  template <typename T, typename... Args>
+  std::enable_if_t<std::is_same<T, cudf::dictionary32>::value, std::pair<src_buf_info*, size_type>>
+  operator()(Args&&...)
+  {
+    CUDF_FAIL("Unsupported type");
+  }
+
  private:
   std::pair<src_buf_info*, size_type> add_null_buffer(column_view const& col,
                                                       src_buf_info* current,
@@ -599,17 +605,6 @@ std::pair<src_buf_info*, size_type> buf_info_functor::operator()<cudf::struct_vi
                                offset_depth);
 }
 
-template <>
-std::pair<src_buf_info*, size_type> buf_info_functor::operator()<cudf::dictionary32>(
-  column_view const& col,
-  src_buf_info* current,
-  int offset_stack_pos,
-  int parent_offset_index,
-  int offset_depth)
-{
-  CUDF_FAIL("Unsupported type");
-}
-
 template <typename InputIter>
 std::pair<src_buf_info*, size_type> setup_source_buf_info(InputIter begin,
                                                           InputIter end,
@@ -1023,7 +1018,7 @@ std::vector<packed_table> contiguous_split(cudf::table_view const& input,
   {
     constexpr size_type block_size = 256;
     copy_partition<block_size><<<num_bufs, block_size, 0, stream.value()>>>(
-      num_src_bufs, num_partitions, d_src_bufs, d_dst_bufs, d_dst_buf_info);
+      num_src_bufs, d_src_bufs, d_dst_bufs, d_dst_buf_info);
   }
 
   // DtoH dst info (to retrieve null counts)

cpp/src/copying/copy.cu

@@ -241,43 +241,14 @@ std::unique_ptr<column> scatter_gather_based_if_else(Left const& lhs,
   //   1. Struct scalars are not yet available.
   //   2. List scalars do not yet support explosion to a full column.
   CUDF_FAIL("Scalars of nested types are not currently supported!");
+  (void)lhs;
+  (void)rhs;
+  (void)size;
+  (void)is_left;
+  (void)stream;
+  (void)mr;
 }
 
-/**
- * @brief Specialization of copy_if_else_functor for list_views.
- */
-template <>
-struct copy_if_else_functor_impl<list_view> {
-  template <typename Left, typename Right, typename Filter>
-  std::unique_ptr<column> operator()(Left const& lhs,
-                                     Right const& rhs,
-                                     size_type size,
-                                     bool left_nullable,
-                                     bool right_nullable,
-                                     Filter filter,
-                                     rmm::cuda_stream_view stream,
-                                     rmm::mr::device_memory_resource* mr)
-  {
-    return scatter_gather_based_if_else(lhs, rhs, size, filter, stream, mr);
-  }
-};
-
-template <>
-struct copy_if_else_functor_impl<struct_view> {
-  template <typename Left, typename Right, typename Filter>
-  std::unique_ptr<column> operator()(Left const& lhs,
-                                     Right const& rhs,
-                                     size_type size,
-                                     bool left_nullable,
-                                     bool right_nullable,
-                                     Filter filter,
-                                     rmm::cuda_stream_view stream,
-                                     rmm::mr::device_memory_resource* mr)
-  {
-    return scatter_gather_based_if_else(lhs, rhs, size, filter, stream, mr);
-  }
-};
-
 /**
  * @brief Functor called by the `type_dispatcher` to invoke copy_if_else on combinations
  *        of column_view and scalar
@@ -293,6 +264,12 @@ struct copy_if_else_functor {
                                      rmm::cuda_stream_view stream,
                                      rmm::mr::device_memory_resource* mr)
   {
+    if constexpr (std::is_same_v<T, cudf::list_view> or std::is_same_v<T, cudf::struct_view>) {
+      (void)left_nullable;
+      (void)right_nullable;
+      return scatter_gather_based_if_else(lhs, rhs, size, filter, stream, mr);
+    }
+
     copy_if_else_functor_impl<T> copier{};
     return copier(lhs, rhs, size, left_nullable, right_nullable, filter, stream, mr);
   }

cpp/src/copying/copy_range.cu

@@ -90,17 +90,6 @@ struct out_of_place_copy_range_dispatch {
   cudf::column_view const& source;
   cudf::column_view const& target;
 
-  template <typename T, CUDF_ENABLE_IF(not cudf::is_rep_layout_compatible<T>())>
-  std::unique_ptr<cudf::column> operator()(
-    cudf::size_type source_begin,
-    cudf::size_type source_end,
-    cudf::size_type target_begin,
-    rmm::cuda_stream_view stream,
-    rmm::mr::device_memory_resource* mr = rmm::mr::get_current_device_resource())
-  {
-    CUDF_FAIL("Unsupported type for out of place copy.");
-  }
-
   template <typename T, CUDF_ENABLE_IF(cudf::is_rep_layout_compatible<T>())>
   std::unique_ptr<cudf::column> operator()(
     cudf::size_type source_begin,
@@ -122,6 +111,13 @@ struct out_of_place_copy_range_dispatch {
 
     return p_ret;
   }
+
+  template <typename T, typename... Args>
+  std::enable_if_t<not cudf::is_rep_layout_compatible<T>(), std::unique_ptr<cudf::column>>
+  operator()(Args...)
+  {
+    CUDF_FAIL("Unsupported type for out of place copy.");
+  }
 };
 
 template <>
@@ -212,17 +208,6 @@ std::unique_ptr<cudf::column> out_of_place_copy_range_dispatch::operator()<cudf:
                                 null_count);
 }
 
-template <>
-std::unique_ptr<cudf::column> out_of_place_copy_range_dispatch::operator()<cudf::list_view>(
-  cudf::size_type source_begin,
-  cudf::size_type source_end,
-  cudf::size_type target_begin,
-  rmm::cuda_stream_view stream,
-  rmm::mr::device_memory_resource* mr)
-{
-  CUDF_FAIL("list_view type not supported");
-}
-
 }  // namespace
 
 namespace cudf {

cpp/src/copying/get_element.cu

@@ -171,12 +171,9 @@ struct get_element_functor {
                                                    mr);
   }
 
-  template <typename T, std::enable_if_t<std::is_same<T, struct_view>::value> *p = nullptr>
-  std::unique_ptr<scalar> operator()(
-    column_view const &input,
-    size_type index,
-    rmm::cuda_stream_view stream,
-    rmm::mr::device_memory_resource *mr = rmm::mr::get_current_device_resource())
+  template <typename T, typename... Args>
+  std::enable_if_t<std::is_same<T, struct_view>::value, std::unique_ptr<scalar>> operator()(
+    Args &&...)
   {
     CUDF_FAIL("get_element_functor not supported for struct_view");
   }

cpp/src/copying/scatter.cu

@@ -142,25 +142,17 @@ struct column_scalar_scatterer_impl<string_view, MapIterator> {
 
 template <typename MapIterator>
 struct column_scalar_scatterer_impl<list_view, MapIterator> {
-  std::unique_ptr<column> operator()(std::reference_wrapper<const scalar> const& source,
-                                     MapIterator scatter_iter,
-                                     size_type scatter_rows,
-                                     column_view const& target,
-                                     rmm::cuda_stream_view stream,
-                                     rmm::mr::device_memory_resource* mr) const
+  template <typename... Args>
+  std::unique_ptr<column> operator()(Args&&...) const
   {
     CUDF_FAIL("scatter scalar to list_view not implemented");
   }
 };
 
 template <typename MapIterator>
 struct column_scalar_scatterer_impl<struct_view, MapIterator> {
-  std::unique_ptr<column> operator()(std::reference_wrapper<const scalar> const& source,
-                                     MapIterator scatter_iter,
-                                     size_type scatter_rows,
-                                     column_view const& target,
-                                     rmm::cuda_stream_view stream,
-                                     rmm::mr::device_memory_resource* mr) const
+  template <typename... Args>
+  std::unique_ptr<column> operator()(Args&&...) const
   {
     CUDF_FAIL("scatter scalar to struct_view not implemented");
   }

cpp/src/copying/segmented_shift.cu

@@ -205,38 +205,6 @@ struct segmented_shift_functor<string_view> {
   }
 };
 
-/**
- * @brief Segmented shift specialization for `list_view`.
- */
-template <>
-struct segmented_shift_functor<list_view> {
-  std::unique_ptr<column> operator()(column_view const& segmented_values,
-                                     device_span<size_type const> segment_offsets,
-                                     size_type offset,
-                                     scalar const& fill_value,
-                                     rmm::cuda_stream_view stream,
-                                     rmm::mr::device_memory_resource* mr)
-  {
-    CUDF_FAIL("segmented_shift does not support list_view yet");
-  }
-};
-
-/**
- * @brief Segmented shift specialization for `struct_view`.
- */
-template <>
-struct segmented_shift_functor<struct_view> {
-  std::unique_ptr<column> operator()(column_view const& segmented_values,
-                                     device_span<size_type const> segment_offsets,
-                                     size_type offset,
-                                     scalar const& fill_value,
-                                     rmm::cuda_stream_view stream,
-                                     rmm::mr::device_memory_resource* mr)
-  {
-    CUDF_FAIL("segmented_shift does not support struct_view yet");
-  }
-};
-
 /**
  * @brief Functor to instantiate the specializations for segmented shift and
  * forward arguments.

cpp/src/copying/shift.cu

@@ -46,8 +46,7 @@ inline bool __device__ out_of_bounds(size_type size, size_type idx)
 
 struct shift_functor {
   template <typename T, typename... Args>
-  std::enable_if_t<not cudf::is_fixed_width<T>(), std::unique_ptr<column>> operator()(
-    Args&&... args)
+  std::enable_if_t<not cudf::is_fixed_width<T>(), std::unique_ptr<column>> operator()(Args&&...)
   {
     CUDF_FAIL("shift does not support non-fixed-width types.");
   }